Railway traffic controlling system



Sept 22, 1931.

FIG. 1.

A. T. CARTER Filed Jan. 11 1930 2 Sheets-Sheet l Sept. 22, 1931. A. T. CARTER 1,824,120

RAILWAY TRAFFIC CONTROLLING SYSTEM Filed Jan. '11. 1930 2 Sheets-Sheet 2 FIGZ.

ATTORNEY Patented Sept. 22, 1931 UNITED STATES ATEN OFFICE AINSLIE 'r. CARTER, or COLDWATER, new YORK, Assmn'on. TOIGENERAL RAILWAY SIGNAL oournmnnr ROQHESTEB, NEW YORK RAILWAY ammo eon'rnomme srsrrm Application filed vlanunry lLlmp Serial No. 420,254,

This invention relates to power operated control apparatus for trafiic C(Jntrollingsystems, and more particularly pertains to con-j trol apparatus for the remote control of reversible motors used in railroad switch machines, car retarders and the like,

In'remote control of such reversible motors, it is often desirable to operate the motor from a local source of electric current supply, which source of supply controlled by a local circuit controller that is in turn governed from a distant tower. It is further desirable that such reversible motors may be provided with some type of overload protective device which may be remote'lyrestored to a normal condition. In a control system of this kind, the overload protective device is operably controlled by the operating current flowing in the local motor circuit. In such cases where only aflternati current power is available for the loc dl source of supply, it would naturally seem that the overload protective device or devices must necessarily be operated on alternating current.

It has been found, however, much more desirable to provide overload protective devices which are operable on direct current inasmuch as their overload characteristics and time characteristics may be more readily determined and more" readily designed to meet the characteristic conditions produced by motors used in switch machines, car -reta-rders and the like. I

With the above andnther considerations in mind, it is proposed in accordance with the present invention to provide the remote-con trol of a reversible motor with cut-nut devices which are opembleupon director unidirectional current in combination with the operation of the motor by alternating current; and it is further. pro .osed that these cut-out devices shall be of :tliie remotely'reset type which operate in conjunction with the reversirw control means for the motor.

' thereof progresses.

In describing the invention in detail, reference will be made to the accompanying drawings, in which like reference characters refer to corresponding parts throughout the several views, and inwhich Fig. 1 represents in a diagrammatic manner one embodiment of the present invention as applied to the control of a typical switch machine;

Fig. '2 represents in a diagrammatic manner a modified form of the embodiment of the present invention shown in Fig. 1; 1.- Fig. .3 represents in a diagrammatic manner another modifiedctorm of the embodiment of the present invention shown in Fig v a a 'Fig. 4 represents in a diagrammatic man ner .a third modified form of the present invention shown in Fig. 1.

With reference to Fig. 1 of the accompanying drawings, atrack switch TS is indicated as operated by. a switch machine SM in the usual well known manner. This switch machine SM is of the usual well known type, such for example, as shown in the patent to K. Howe, Patent No. 1,466,903., dated Sept. 4, 1923., with control apparatus to accomzplish the reversibility of the switch machine as'provided by the embodiments of the present invention. The track switch TS, as controlled by the switch machine .SM, routes tnaflic over a main track MT, or onto a side track :53 as respectively determined by the normal or reverse positions .ot the track switch TS. v

' The switch machine :SM includes a motor Mha'ving an armature A. and afield winding F which are controlled over normal or reverse operatingcircuits in a manner to operate the armature A in one direction or the othen. The control apparatus" includes a normal circuit controller N and .a'reverse circuit controller R which respectively close the normal and reverse operating circuits of thelmotor M. This motor is supplied with operating power from an alternating current source represented as an alternator ALT over a suitable transmission line. Associated with the'normal and reverse .operating'icircuits of the switch machine :motor circuit controller N or R by mechanical means as diagrammaticallyrepresented in the drawings. I k j j f Included in the normal and reverse operin ircuit of the motor are the current i .v o at g C S the control relay E.over a normal energiztransformers T and T respectively. These transformers are of usuallcurrent tlie"battery BT' u pon its left-hand terminal forming type as distinctive from the constant potential type of transformer; In other words, the transformers T and T are of the type which have low reactance primaries when the secondaries are shunted or carrying a load. The secondary windings of these current transformers T and T energize respectively the windingsof the normal and reverse overload devices ON and OR the circuits of which have included therewith respectively, full wave rectifier units R and R It is thus seen that the current flow in the overload devices ONand OR will be proportional to the current flow in the operating circuits of the'switch machine but will be uni-directional.

Associated with the circuit controllersN and R is a polarized control relay E having contact means which are operated to either of two extreme biased positions, in

" which they remain until therelay is energized with an opposite polarity.

Two movable contacts 5 and Gare operated from extreme positionsto intermediate po-' sitions during operation of the switchamas chine by mechanical means associated therewith. In other words, the contact 5 makes contact between a pair of fixed contacts when the switch machine SM is in anormal extreme position and makes contact be tween the same pair of fixed contacts dur-' ing the operation of the switchmachine, as it is then in an intermediate contacting position. Also, the movable contact G'makes contact between a pair of fixed contacts when the switch machine is in a reirerselexe: treme position and 'makes contact between the same pair of fixed contacts during the operation of the switch machine as it is in an intermediate contacting position.

A rectifier'unit R provides uni-directional current for the operation of the circuit controllers N and R. In the tower a lever L is provided which is operable to eitheriof two extreme posi-v tions to determine the polarity applied to the remotely controlled relay E located at the switch machine. This olarized circuit is supplied with energy rom a suitable source shown as. a battery BT."

It is believed that the interrelation of the various devices, the operation and circuits of this embodiment of the present invention will be best understood by further description being given from the standpoint of operation.

f"? 2 1 I :Operation The various devices and circuits are shown in a normal at rest condition with the track switch; TS -in a normal -locked condition. yThe "lever L in the 'tower T is in a corresponding normal position which energizes ing circuit to place positive potential from as is obvious from the drawing.

L Let us assume that theoperator desires to control the track switch TS to a reverse position. f To do this, he moves the lever L toa lefthand position placing negative polari'ty'upon theleft-hand terminal of the control relayE, as is obvious from the drawing; The polar contact 7 of the relay E then operates'to'a left-hand dotted line po sition which closes ,the energizing circuit for the reverse circuit controller B. This energizing circuit for the circuit controller Rf'is traced as follows :-from the upper terminal of the alternating current source ALT, through the wires 10,11, '12 and 13, winding of reverse "circuit controller R, wire 14, closed contact 15 of'the reverse overload device QR, wire 16, contacts 5-17, wire 18, contact 7' of theremote control relay E in a dotted lineposition, wire 19, rectifier unit R,'wires 20 and '21, to the lower terminal of the alternating current source ALT. The current which flows in this circuit is unidirectional and causes the reverse circuit controllerR to be energized, which then operates its contact 24 to a dotted line position in' which the reverse [operating circuit of the switchrrnachine'motor M is then closed. I The reverse operating circuit for the switch machine motor M is traced as follower-from the upper terminal of the alternating current source ALT, through wires,10,- 11,-12, 25 and 26, contact 27 of normal circuit controller N in a deenergized full line position, wire 28,'windings of armature A,*wire 29, contact 24 of reverse circuit. controllerR in-an energized dotted line position, wire 30, primary winding 9 of current transformer T ywires 31 and 32, field winding'F, wires 33, 34 and 21 to the'lower terminal .of the alternating current source ALT. Alternating current flows in this circuit causing the switchmachine SM to unlockthetrac'k switchTS and operate it toward a reverse position. After the initiation of the operation of the switch machine and shortly before thetrack switch TS is unlocked, thelmovable contacts 5 and 6 are mechani'cally operated to intermediate positions.

lVith thecontacts 5 and 6 in intermediate positions, the energizing circuit of the reverse circuit controller R is still established and the circuit for the normal circuit controller N could be established if the control relay E were energized with opposite polarity. In other words, with the movable contacts 5 and 6 in intermediate positions either one of the circuit controllers N or R may be energized in accordance with the position of the polar contact 7 of the remote control relay E. The reversibility of the switch machine in midstrolre is thereby provided.

Should the track switch TS, for one reason or another, become stuck or blocked, the switch machine motor M would then be re quired to operate against a friction clutch (not shown) under a greatly increased load which would cause a very heavy operating current'to flow. This heavy operating current would fiow through the primary winding 9 of the current transformer T through the circuit as heretofore traced. This heavy current would induce an alternating current in the secondary winding of the current transformer T according to the ratio of the transformation. However, the alternating current in the secondary winding would not be able to flow in both directions in the overload device OR but is rectified by the rectifier unit R allowing a uni-directional current to flow through the winding of device OR.

This circuit for the reverse overload device R is traced from the lower terminal of the secondary winding23 of the current transformer T through the wire 35, rectiiier section 36, wire 37, winding of reverse overload device OR, wire 38, rectifier sec-- tion 39, and wire 40 to the opposite terminal of the secondary of transformer T on one half of the alternating current wave. The other half of the wave flows from the upper terminal of the secondary winding 23 of the current transformer T through wire 40, rectifier section 41, wire 37, winding of overload device OR, wire 38, rectifier section 42, wire 35, to the opposite terminal of the secondary of transformer T lf theeXcessive overload persists on the swi ch machine motor for a certain predetermined time, the reverse overload device OR actuates its armature 51 thereby releasing the contact 15. The contact 15 then assumes a dotted line biased position in which the energizing circuit for the reverse circuit controller R is opened. As soon as the reverse circuit controller R is deenergized the contact 24 assumes a normal full line position in which the reverse operating circuit of the switch machine motor M is opened.

The operator may then return the lever L to its normal position in which positive potential is applied to the remote control relay E. As the switch machine is in midstroke, the movable contacts 5 and 6 are in intermediate positions so that as soon as the relay E is energized with positive potential and the contact 7 returns to a normal position, the energizing circuit for the normal circuit controller N is completed. The normal circuit controller N is energized over a circuit traced as follows :-from the upper terminal of the alternating current source ALT, through wires 10, 11 and 43, winding of normal circuit controller N, wire 44, contact 45 of normal overload device ON in a normal full line position, wire 46, contacts 6-47, wire 48, contact 7 of relay E in 9. normal position, wire 19, rectifier unit R wires 20 and 21, to the lower terminal of the alternating current source ALT;

When the normal circuit controller N is energized, its contact 27 is moved to a dotted line position which causes a reset arm 49 to restore the contact 15 of the reverse overload device OR to a normal contacting position in which it is latched by the armature 51. Also, the normal operating circuit of the switch machine motor is then closed causing it to return the track switch TS to its normal locked condition.

The normal operating circuit for the switch machine motor M is traced as follows :from the upper terminal of the alternating current source ALT, through wires 10, 11, 12, 25 and 50, contact 24 of reverse circuit controller R in a normal posi tion, wire 29, windings of armature A, wire 28, contact 27 of normal circuit controller N in a dotted line energized position, wire 52, primary winding 8 of current transformer T wire 32, field winding F, wires 33, 34 and 21, to the lower terminal of the alternating current source ALT.

During the completion of the normal operating circuit, the motor M is protected from excessive overloads by the device ON which has an energizing circuit including a rectifier unit R and the secondary winding 22 of current transformer T in a similar manner as described in detail for overload device OR.

When the switch machine SM has operated the track switch to its former normal locked condition, the movable contacts 5 and 6 are returned to their normal extreme positions which opens the energizing circuit for the normal circuit controller N which in turn opens the normal operating circuit for the switch machine motor.

If the track switch TS does not encounter a barrier of one kind or another in its operation from the normal position to the reverse position, the overload device OR will not operate, thereby allowing the track switch to complete its operation to a full reverse locked condition. As soon as the track switch TS is in a reverse locked posit-ion, the movable cont-acts 5 and 6 assume extreme reverse positions which open the energizing circuit for the reverse circuit controller R thereby in turn opening the reverse operating circuit for the switch machine motor.

With reference to Fig. 2 of the accompanying drawings, a modified form of the embodiment of the present invention, as shown in Fig. 1, provides the replacement of the two current transformers T and T by a single current transformer T and also the replacement of the two rectifier units R and R by a single rectifier unit R This is accomplished by the provision of extra contacts 55 and 56 on the reverse and normal circuit controllers R and N respectively. The operating circuits of the motor M are closed by the contacts 27 and 24 while the selection of the corresponding normal or reverse overload device ON or OR is determined by the extra contacts 56 and 55 on the circuit controllers N a and R respectively, which are included in the energizing circuits of the normal and reverse overload devices respectively. The operation of a system with the circuit arrangement as shown is similar to that described for Fig. 1 and need not be set forth in detail. The same devices are given the same reference characters with distinctive exponents a which makes it obvious that the wires 46, 16, 11 and 33 of Fig. l are replaced respectively by the wires 46*, 16 11 and 33 in Fig. 2.

With reference to Fig. 3, a second modification of the embodiment of the invent-ion, as shown in Fig. 1, provides the replacement of the two current transformers T and T of Fig. 1 by the single current transformer T and also provides the replacement of the two rectifier units R and R by the single rectifier unit R The operating circuits of the motor M are completed by the contacts 2 1" and 27 of the reverse and normal circuit controllers R and N respectively. The primary winding of the current transformer T is included in both of these circuits, while its secondary is connected to the rectifier unit R The rectified or uni-directional current, provided by the rectifier unit R is supplied to either the normal overload device ON or the reverse overload device OR in accordance with an extra contact 57 on the control relay E. This contact 57 has the same functions as the two extra contacts 55 and 56 of Fig. 2. The devices of Fig. 3 which are the same as those of Fig. 1 have the same reference characters with distinctive exponents b, which makes it obvious that the wires 16, 16, 11 and 33 of Fig. 1 are replaced by the wires 46 16 11 and 33 of Fig. 3.

Although the rectifier units R R R and R areconventionally shown as a group of four sections in bridge connection for full wave rectification, it is to be understood that half-wave rectifiers may also be used when the various constants and characteristics of the circuits are so designed and arranged. Also, the conventional showing is intended to represent any suitable type full-wave rectifier, such as the dry plate copper oxide type, solution type, or of the vacuum tube type.

With reference to Fig. 4 half-wave rectifiers R and R are provided to replace the rectifier units R and R of Fig. 1 respectively. In Fig. 4 the current transformers T and T are the same current transformers as T and T with their constants and design characteristics suitable for the particular conditions to be met. Similarily, the overload devices ON and OR replace the overload devices ON and OR of Fig. 1.

Although the rectifier unit R, which pro vides uni-directional current for the normal and reverse circuit controllers N and R is shown as a half-wave rectifier, it is to be understood that it may be a full-wave rectifier without altering the operation of the embodiment of the present invention. Various other modifications and adaptations of the present invention may be provided, as

for example, the mechanical stick and re-.

set operation of the embodiment of the present invention may be replaced and adapted for electrical stick and reset operation in a manner such for example, as shown in an application by C. S. Bushnell Ser. No. 108,- 991, dated November 22, 1929.

The overload cut-out devices ON and OR may be of the usual overload type relays; of an inverse time element type relays; or of any other suitable type of overload devices either electro-magnetically or thermally actuated, and have for convenience been shown in a conventional manner.

From the above description, it is seen that control circuits are provided for a reversible motor which are protected from excessive overloads by overload protective devices or cut-outs which are operable on direct or uni-directional current although the operating power of the motor is alternating current. Also, these overload protective devices are provided with means for resetting or restoring them to normal conditions after their functioning during a particular operation.

Having described several forms of control devices and circuits for a reversible motor having overload protection, as embodiments of the present invention, it is desired to beunderstood that these forms are selected to facilitate in the disclosure of the invention rather than to limit the number of forms which it may assume; and, it is to be further understood that various modifications, adaptations and alterations may be apamaze plied to the specific forms shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by'the appended claims.

Having described my invention, I now claim 1. In a traflic controlling system for railroads, an alternating current source, an alternating current power operated reversible motor having normal and reverse operating circuits, two overload protective devices associated with said operating circuits respectively, one of said overload protective devices being effective for opening said normal operating circuit when excessive alternating current flow occurs therein, the other of said overload protective devices being effective for opening said reverse operating circuit when excessive alternating current flow occurs therein, and means for supplying said overload protective devices with uni-directional current of a valve in direct proportion to the alternating current flow in their respective operating circuits.

2. In a trafiic controlling system for railroads, a switch machine, a reversible alternating current motor having a normal operating circuit and a reverse operating circuit, a normal relay for closing said normal op erating circuit, a normal cut-out device for opening said normal operating circuit if the alternating current fiow therein is excessive, said normal cut-out device being operable on uni-directional current only, means for supplying said normal cut-out device with unidirectional current which is proportional to the alternating current flowing in said normal operating circuit, a reverse relay for closing said reverse operating circuit, a reverse cut-out device for opening said reverse operating circuit if the current flow therein is excessive, said reverse cut-out device being operable on uni-directional current only, means for supplying said reverse cut-out device with uni-directional current which is proportional to the alternating current flowing in said reverse operating circuit, and means for restoring said reverse cut-out device when said normal relay is operated and for restoring said normal cut-out device when said reverse relay is operated.

3. In a traffic controlling system for railroads, an alternating current electric motor having normal and reverse operating circuits, means for closing said operating circuits alternately, two current transformers each having a primary and a secondary, one of said current transformers having its primary connected in said normal operating current and the other of said current transformers having its primary connected in said reverse operating circuit, an overload protective device connected tothe secondary of said one current transformer, another overload device connected to the secondary of said othercurrent transformer, meansfor causing the current flow in said one: and said other" overloadprotecti've devices to be unidirectional, means operated by said one overload protective: device for opening said normal operating circuit, meansoperated by said, other overload protective device for openingsaid reverse operating circuit, and means forrestoring said overload devices to normal ,upon the opposite operation of said means for closing said operating circuits.

1 4; In a trafficcontrolling system for railroads, a reversible alternating current motor having normal and reverse operating circuits, a sourceof alternating current power, a; control lever, a'contro-l relay governed by sa-idcontrol lever, normal and ,reverse circuit controllers foropening and closing said normal and reverse operating circuits respectively, an energizing circuit for each of circuit controllers governed by said control relay, means supplying said energizing circuits from said alternating current source with uni-directional current, one cutout device effective to open said normal operating circuit when excessive alternating current flow; occurs therein, means for supplying. said one cut-out deviceswitli uni-directional current in a direct proportion to the alternating current flow in said normal operating circuit-g another cut-out device effectiveatoi open said reverse operating circuit when excessive alternating current flow occurs therein, means for supplying said other 'cut-out device with uni-directional current in direct proportion to the alternating current flow in said reverse operating circuit, and means for restoring said one cutout device when said reverse circuit controllr operated i and for restoring said other cut-out device when said normal circuit' controller is operated.

5. In a trafiic controlling system for railroads, an alternating current source, an alternating current power operated motor having operating circuits, a transformer designed for low operating flux density, said transformer having a primary winding and a secondary winding, said primary winding being included in series with said operating circuits, a rectifier unit, and overload protective means supplied with uni-directional current from said secondary winding through said rectifier unit.

6. In a traffic controlling system for railroads, an alternating current source, an alternating current power operated motor having operating circuits, a transformer having primary and secondary windings, said primary winding being connected in said operion io's

ice

ating circuits, a rectifier unit associated with 7 In a trafiic controlling system for railroads,;an alternating current source, an alternating current power operatedreversible motor having normal and reverse operating Q circuits, a normal circuit controller for clos ing said normal operating circuit, a reverse circuit controller for closing said reverse operating circuit, a current transformer having a primary winding and a secondary 1Q winding, said primary Winding being connected in series with said normal and reverse operating circuits, rectifying means connect ed to said secondary winding, a normal overload cut-out, a reverse overload cut-out, and means supplying uni-directional current from said rectifying means to said normal overload cut-out when said normal circuit controller is actuated and to said reverse overload cut-out when said reverse circuit controller is actuated. I

8. In a traflic controlling system for railroads, an alternating current source, an alternating current power operated reversible motor having normal and reverse operating circuits, a remotely governed control relay, means operated by said control relay .for opening and closing said normal and reverse operating circuits, a current transformer having a primary and a secondary Winding, said primary winding being connected in series in said normal and reverse operating circuits, a rectifier connected to said secondary winding, a normal overload cut-out, a reverse overload cut-out, and a means supplying uni-directional current from said rectifier to either said normal overload cut-out or to said reverse overload cut-out in accordance with said control relay.

" 9 In testimony whereof I afiix my signature.

- AINSLIE T. CARTER. 

